I feel that I am being unfairly treated at work for last year. Do I have any legal rights?

There are 14 of us that work in my department. I am the 3rd in seniority. I have worked in this department for 18 years with no other problems. Four girls routinely tell the supervisor on me for the last year. The supervisor believes them. There is no investigation into the details except with these 4 girls. Every time they tell, I am brought into the office. I tell my side of the story and then I am reprimanded without any investigation. It is usually is a slap on the hand. However I have had a correction action brought against me with counseling. These girls also talk bad about me spreading rumors with other co-workers to the point where I have no credibility. I try to remain quit and mind my business. It is getting so bad I feel sick to my stomach to go in. What can I do about this? I have seen others go to human resources. They just bring the case back down to the supervisor. I have started to voice record my times in the office so I have proof.